LS = small group of friends willing to chitchat. Supposed to be a 10- members stuff.

Company = big deal. You're supposed to have only one, supposed to do missions and events based on it...i'd say it will be, pretty much, the "real" allegiance of your character. Probably the faction ranks might be related to companies too, like turfs control at FFTA and nation control at FFXI.

However...i wonder if anyone will be able to actually create a company (assuming an obscene amount of gil for it if so) or if we will join one of several previously created companies, Sahaleen Sentinels-style, where you can grow in theirs ranks once you join and gets it reseted if you leave.